/* crypto/dsa/dsa.h */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

/*
 * The DSS routines are based on patches supplied by
 * Steven Schoch <schoch@sheba.arc.nasa.gov>.  He basically did the
 * work and I have just tweaked them a little to fit into my
 * stylistic vision for SSLeay :-) */

#ifndef HEADER_DSA_H
#define HEADER_DSA_H

#include <openssl/e_os2.h>

#ifdef OPENSSL_NO_DSA
#error DSA is disabled.
#endif

#ifndef OPENSSL_NO_BIO
#include <openssl/bio.h>
#endif
#include <openssl/crypto.h>
#include <openssl/ossl_typ.h>

#ifndef OPENSSL_NO_DEPRECATED
#include <openssl/bn.h>
#ifndef OPENSSL_NO_DH
# include <openssl/dh.h>
#endif
#endif

#ifndef OPENSSL_DSA_MAX_MODULUS_BITS
# define OPENSSL_DSA_MAX_MODULUS_BITS 10000
#endif

#define DSA_FLAG_CACHE_MONT_P         0x01
#define DSA_FLAG_NO_EXP_CONSTTIME     0x02   /* new with 0.9.7h; the built-in DSA
                                              * implementation now uses constant time
                                              * modular exponentiation for secret exponents
                                              * by default. This flag causes the
                                              * faster variable sliding window method to
                                              * be used for all exponents.
                                              */

/* If this flag is set the DSA method is FIPS compliant and can be used
 * in FIPS mode. This is set in the validated module method. If an
 * application sets this flag in its own methods it is its reposibility
 * to ensure the result is compliant.
 */

#define DSA_FLAG_FIPS_METHOD          0x0400

/* If this flag is set the operations normally disabled in FIPS mode are
 * permitted it is then the applications responsibility to ensure that the
 * usage is compliant.
 */

#define DSA_FLAG_NON_FIPS_ALLOW       0x0400

#ifdef  __cplusplus
extern "C" {
#endif

/* Already defined in ossl_typ.h */
/* typedef struct dsa_st DSA; */
/* typedef struct dsa_method DSA_METHOD; */

typedef struct DSA_SIG_st {
    BIGNUM *r;
    BIGNUM *s;
} DSA_SIG;

struct dsa_method {
    const char *name;
    DSA_SIG * (*dsa_do_sign)(const unsigned char *dgst, int dlen, DSA *dsa);
    int (*dsa_sign_setup)(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
                          BIGNUM **rp);
    int (*dsa_do_verify)(const unsigned char *dgst, int dgst_len,
                         DSA_SIG *sig, DSA *dsa);
    int (*dsa_mod_exp)(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
                       BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
                       BN_MONT_CTX *in_mont);
    int (*bn_mod_exp)(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
                      const BIGNUM *m, BN_CTX *ctx,
                      BN_MONT_CTX *m_ctx);           /* Can be null */
    int (*init)(DSA *dsa);
    int (*finish)(DSA *dsa);
    int flags;
    char *app_data;
    /* If this is non-NULL, it is used to generate DSA parameters */
    int (*dsa_paramgen)(DSA *dsa, int bits,
                        const unsigned char *seed, int seed_len,
                        int *counter_ret, unsigned long *h_ret,
                        BN_GENCB *cb);
    /* If this is non-NULL, it is used to generate DSA keys */
    int (*dsa_keygen)(DSA *dsa);
};

struct dsa_st {
    /* This first variable is used to pick up errors where
     * a DSA is passed instead of of a EVP_PKEY */
    int pad;
    long version;
    int write_params;
    BIGNUM *p;
    BIGNUM *q;          /* == 20 */
    BIGNUM *g;

    BIGNUM *pub_key;      /* y public key */
    BIGNUM *priv_key;     /* x private key */

    BIGNUM *kinv;       /* Signing pre-calc */
    BIGNUM *r;          /* Signing pre-calc */

    int flags;
    /* Normally used to cache montgomery values */
    BN_MONT_CTX *method_mont_p;
    int references;
    CRYPTO_EX_DATA ex_data;
    const DSA_METHOD *meth;
    /* functional reference if 'meth' is ENGINE-provided */
    ENGINE *engine;
};

#define d2i_DSAparams_fp(fp, x)  (DSA *)ASN1_d2i_fp((char *(*)())DSA_new, \
                                                    (char *(*)())d2i_DSAparams, (fp), (unsigned char **)(x))
#define i2d_DSAparams_fp(fp, x)  ASN1_i2d_fp(i2d_DSAparams, (fp), \
                                             (unsigned char *)(x))
#define d2i_DSAparams_bio(bp, x) ASN1_d2i_bio_of(DSA, DSA_new, d2i_DSAparams, bp, x)
#define i2d_DSAparams_bio(bp, x) ASN1_i2d_bio_of_const(DSA, i2d_DSAparams, bp, x)

DSA * DSAparams_dup(DSA *x);
DSA_SIG * DSA_SIG_new(void);
void    DSA_SIG_free(DSA_SIG *a);
int     i2d_DSA_SIG(const DSA_SIG *a, unsigned char **pp);
DSA_SIG * d2i_DSA_SIG(DSA_SIG **v, const unsigned char **pp, long length);

DSA_SIG * DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
int     DSA_do_verify(const unsigned char *dgst, int dgst_len,
                      DSA_SIG *sig, DSA *dsa);

const DSA_METHOD * DSA_OpenSSL(void);

void    DSA_set_default_method(const DSA_METHOD *);
const DSA_METHOD * DSA_get_default_method(void);
int     DSA_set_method(DSA *dsa, const DSA_METHOD *);

DSA *   DSA_new(void);
DSA *   DSA_new_method(ENGINE *engine);
void    DSA_free(DSA *r);
/* "up" the DSA object's reference count */
int     DSA_up_ref(DSA *r);
int     DSA_size(const DSA *);
/* next 4 return -1 on error */
int     DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
int     DSA_sign(int type, const unsigned char *dgst, int dlen,
                 unsigned char *sig, unsigned int *siglen, DSA *dsa);
int     DSA_verify(int type, const unsigned char *dgst, int dgst_len,
                   const unsigned char *sigbuf, int siglen, DSA *dsa);
int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                         CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func);
int DSA_set_ex_data(DSA *d, int idx, void *arg);
void * DSA_get_ex_data(DSA *d, int idx);

DSA *   d2i_DSAPublicKey(DSA **a, const unsigned char **pp, long length);
DSA *   d2i_DSAPrivateKey(DSA **a, const unsigned char **pp, long length);
DSA *   d2i_DSAparams(DSA **a, const unsigned char **pp, long length);

/* Deprecated version */
#ifndef OPENSSL_NO_DEPRECATED
DSA *   DSA_generate_parameters(int bits,
                                unsigned char *seed, int seed_len,
                                int *counter_ret, unsigned long *h_ret, void
                                (*callback)(int, int, void *), void *cb_arg);
#endif /* !defined(OPENSSL_NO_DEPRECATED) */

/* New version */
int     DSA_generate_parameters_ex(DSA *dsa, int bits,
                                   const unsigned char *seed, int seed_len,
                                   int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);

int     DSA_generate_key(DSA *a);
int     i2d_DSAPublicKey(const DSA *a, unsigned char **pp);
int     i2d_DSAPrivateKey(const DSA *a, unsigned char **pp);
int     i2d_DSAparams(const DSA *a, unsigned char **pp);

#ifndef OPENSSL_NO_BIO
int     DSAparams_print(BIO *bp, const DSA *x);
int     DSA_print(BIO *bp, const DSA *x, int off);
#endif
#ifndef OPENSSL_NO_FP_API
int     DSAparams_print_fp(FILE *fp, const DSA *x);
int     DSA_print_fp(FILE *bp, const DSA *x, int off);
#endif

#define DSS_prime_checks 50
/* Primality test according to FIPS PUB 186[-1], Appendix 2.1:
 * 50 rounds of Rabin-Miller */
#define DSA_is_prime(n, callback, cb_arg) \
    BN_is_prime(n, DSS_prime_checks, callback, NULL, cb_arg)

#ifndef OPENSSL_NO_DH
/* Convert DSA structure (key or just parameters) into DH structure
 * (be careful to avoid small subgroup attacks when using this!) */
DH * DSA_dup_DH(const DSA *r);
#endif

#define EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits) \
    EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA, EVP_PKEY_OP_PARAMGEN, \
                      EVP_PKEY_CTRL_DSA_PARAMGEN_BITS, nbits, NULL)

#define EVP_PKEY_CTRL_DSA_PARAMGEN_BITS   (EVP_PKEY_ALG_CTRL + 1)
#define EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS (EVP_PKEY_ALG_CTRL + 2)
#define EVP_PKEY_CTRL_DSA_PARAMGEN_MD     (EVP_PKEY_ALG_CTRL + 3)

/* BEGIN ERROR CODES */
/* The following lines are auto generated by the script mkerr.pl. Any changes
 * made after this point may be overwritten when the script is next run.
 */
void ERR_load_DSA_strings(void);

/* Error codes for the DSA functions. */

/* Function codes. */
#define DSA_F_D2I_DSA_SIG                 110
#define DSA_F_DO_DSA_PRINT                104
#define DSA_F_DSAPARAMS_PRINT             100
#define DSA_F_DSAPARAMS_PRINT_FP          101
#define DSA_F_DSA_DO_SIGN                 112
#define DSA_F_DSA_DO_VERIFY               113
#define DSA_F_DSA_GENERATE_KEY            124
#define DSA_F_DSA_GENERATE_PARAMETERS_EX  123
#define DSA_F_DSA_NEW_METHOD              103
#define DSA_F_DSA_PARAM_DECODE            119
#define DSA_F_DSA_PRINT_FP                105
#define DSA_F_DSA_PRIV_DECODE             115
#define DSA_F_DSA_PRIV_ENCODE             116
#define DSA_F_DSA_PUB_DECODE              117
#define DSA_F_DSA_PUB_ENCODE              118
#define DSA_F_DSA_SIGN                    106
#define DSA_F_DSA_SIGN_SETUP              107
#define DSA_F_DSA_SIG_NEW                 109
#define DSA_F_DSA_SIG_PRINT               125
#define DSA_F_DSA_VERIFY                  108
#define DSA_F_I2D_DSA_SIG                 111
#define DSA_F_OLD_DSA_PRIV_DECODE         122
#define DSA_F_PKEY_DSA_CTRL               120
#define DSA_F_PKEY_DSA_KEYGEN             121
#define DSA_F_SIG_CB                      114

/* Reason codes. */
#define DSA_R_BAD_Q_VALUE                 102
#define DSA_R_BN_DECODE_ERROR             108
#define DSA_R_BN_ERROR                    109
#define DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE 100
#define DSA_R_DECODE_ERROR                104
#define DSA_R_INVALID_DIGEST_TYPE         106
#define DSA_R_MISSING_PARAMETERS          101
#define DSA_R_MODULUS_TOO_LARGE           103
#define DSA_R_NEED_NEW_SETUP_VALUES       110
#define DSA_R_NON_FIPS_DSA_METHOD         111
#define DSA_R_NO_PARAMETERS_SET           107
#define DSA_R_PARAMETER_ENCODING_ERROR    105

#ifdef  __cplusplus
}
#endif
#endif
